Intel has released its flagship 18-core, behemoth Core i9-7980XE and its slightly smaller sibling, the 16-core Core i9-7960X. Officially, disclosed all the way back in May, the new processors are launching now to impend AMD Threadripper firestorm.

Designed for mega-taskers and multi-core lovers, Intel says that its Core X-series products are the company's "Most Powerful, Most Scalable" desktop processors to date. When you consider they scale from a quad-core part with only 16 PCI Express lanes, all the way on up to a monolithic 18-core chip with 44 integrated PCIe lanes, scalable certainly does come to mind.

The 18-core Core i9-7980XE and 16-core Core i9-7960X both feature HyperThreading, hence the support for 36 and 32 processing threads with these 18 and 16 core processors. They both have the same number of PCIe lanes (44), support for quad-channel DDR4 at official speeds of up to 2666MHz, 165 watt TDPs, and similar support for an array of Intel technologies. Both chips also leverage the same LGA 2066 socket and X299-chipset as well. Their differences are spotted in their base and turbo clocks, total cache, and their max TJunction temperature.

It's also worth noting that Intel's Virtual Raid On CPU (VROC) feature-which allows you to link several M.2 NVMe SSDs in a bootable virtual RAID either via on-board M.2 slots, or via an expansion card-remains locked to RAID 0 out of the box. Those wanting to run other types of RAID need to purcahse a small VROC dongle for around $100.

The Core i9-7980XE and Core i9-7960X are both based on Intel’s Skylake-X microarchitecture. and the same 14nm FinFET Skylake-SP architecture of Intel's Xeon server and workstation chips. The architecture features a new AVX-512 instruction set (up from 256-bit-wide AVX) and a new cache hierarchy. Intel has also dramatically redesigned the way each core exchanges data with another, introducing a mesh topology.

It is interesting to see how Intel has used this mesh topology to construct its multicore CPUs compared to AMD. Intel uses its mesh topology to create a single, monolithic die that contains all 16 cores. Theoretically, since all the cores are on the same die—and because Intel can run the mesh at a solid clock speed, regardless of memory timings-data exchanged between each core is quick and consistent.

The drawback is scalability. The more cores Intel crams into a single die, the larger it becomes, the more costly it is to produce, and the hotter it gets. By contrast, AMD has opted for a multichip module (MCM) design for Threadripper. Theadripper is essentially two eight-core Ryzen dies (which are actually just two four-core dies) thrust together onto the same CPU package, and linked together via AMD's Infinity Fabric tech.

While Infinity Fabric does rely on fast DDR4 memory clocks to function at its best, the benefit of the MCM design is that it's far easier to scale to more cores while maintaining reasonable thermals and clock speeds.

Core i9-7980XE

Core i9-7960X

Core i9-7900X

Core i7-7820X

Architecture

Skylake-X

Skylake-X

Skylake-X

Skylake-X

Cores /threads

18C / 36T

16C / 32T

10C / 20T

8C / 16T

Base clock

2.6GHz

2.8GHz

3.3GHz

3.6GHz

TB 2.0 clock

4.2GHz

4.2GHz

4.3GHz

4.3GHz

TB 3.0 clock

4.4GHz

4.4GHz

4.5GHz

4.5GHz

L3

24.75MB

22MB

13.75MB

11MB

PCIe 3.0 lanes

44 lane

44 lane

44 lane

28 lane

Supported memory

DDR4-2666 x 4ch

DDR4-2666 x 4ch

DDR4-2666 x 4ch

DDR4-2666 x 4ch

TDP

165W

165W

140W

140W

Unlocked

Yes

The Core i9-7980XE (Extreme Edition) sits atop the Core X Series line-up. It is packing 18 Skylake-X cores (36 threads with HyperThreading) with a base clock of 2.6GHz and max Turbo 2.0 and Turbo Boost Max 3.0 frequencies of 4.2GHz and 4.4GHz, respectively. The Core i9-7980XE has 24.75MB of shared L3 cache, 1MB of L2 cache per core, and a TDP of 165W

The Core i9-7960X's details are essentially same. Although it has fewer cores, its base clock is 200MHz higher than the flagship Core i9-7980XE. The chip is matching AMD's flagship Threadripper 1950X.
According to the tests we performed using CINEBENCH R15 / CPU, the turbo frequency for the Core i9-7960X tops at 4GHz.